The 24-year-old All-Star had an MRI Monday which revealed the partially-torn UCL ulnar collateral ligament. A source told The News that pitcher was experiencing soreness in his “forearm area.”

Harvey in his first full season in the majors has been the brightest spot in a lost season for the Mets. With a 9-5 record 2.27 ERA and 191 strikeouts in 178 innings Harvey — the National League’s starter in las tmonth’s All-Star Game at Citi Field — and Zack Wheeler are at the front of a Mets rotation that is poised for a breakout season in 2014.

How Harvey factors into the Mets’ plans for next season now is hard to predict. The current plan of action for Harvey is rest but surgery could be required.